摘要
采用XRD、SEM、EDS以及EPMA等分析方法,研究铸态K4169合金及固溶-时效处理后K4169合金在650℃下模拟烟气(75%Na_2SO_4+25%NaCl)环境中的热腐蚀行为.结果表明:2种状态的K4169合金腐蚀动力学曲线均遵从抛物线规律;2种试样的腐蚀产物均分为2层,其内腐蚀层的腐蚀产物为Ni_3S_2;铸态合金的外腐蚀层产物分3部分:最外侧为Ni_3S_2薄层;中间以Fe_3O_4,NiO,NiFe_2O_4等氧化产物为主;内侧以Cr-O为主,有少量的铌、铝、钛的氧化物;固溶-时效态合金外腐蚀层的腐蚀产物为外侧以Fe_3O_4、NiO、NiFe_2O_4为主和内侧以Cr-O为主的2部分构成.2种状态合金的热腐蚀规律均遵循碱性机制.固溶-时效态试样的腐蚀层厚度低于铸态试样,固溶-时效处理能显著提高K4169合金的抗热腐蚀能力.
Hot-corrosion behavior of as-cast K4169 alloy and K4169 alloy processed with solid-solution and ageing treatment were investigated in environment of simulated flue-gas(75%Na2 SO4+25 %NaCl) at 650 ℃ by using analysis means of XRD, SEM, EDS and EPMA. The investigation result showed that the corrosion kinetic curves of K4169 alloys in both states would follow a parabolic law, and the corrosion film structures of two kinds of K4169 alloys are divided into two layers. Their corrosion products would consist of two layers: the inside layer was Ni3S2 and the outer layer corrosion products of as-cast K4169 were com: posed of three part. The most outer part was Ni3Szthin layer, middle part was mainly Fe304, NiO, NiFe2O4 oxidation products, and inside part was Cr-O and a small amount of niobium, aluminum, titanium ox- ide. The outer layer of corrosion products of K4169 alloy processed with solid-solution and ageing treat- ment was composed mainly of Fe3O4, NiO, and NiFe2O4 and the inner layer was mainly Cr--O. Corro- sion behaviors of both K4169 alloys would follow alkaline corrosion mechanism. Corrosion layer thickness of K4169 alloy processed with solid-solution and ageing treatment was less than that of the as-cast sample. The solid-solution and ageing treatment would significantly improve the hot-corrosion resistance of the K4169 alloy.
出处
《兰州理工大学学报》
CAS
北大核心
2016年第1期5-10,共6页
Journal of Lanzhou University of Technology
基金
973国家重点基础研究发展计划(2012CB722806)